Brush and method of making same



Am F, W56 m. o. PETERSUN BRUSH AND METHOD OF MAKING SAME 2 Sheets-Shae: 1.

Filed May 31, 1952 INVENTOR. EFL 5f '0. Ffif/FJU/V WGWA/EYS.

W 1955 R. o. PETERSON 2,757,400

BRUSH AND METHOD OF MAKING SAME Filed May 51, 1952 2 Sheets-sheaf 2 I IN VEN TOR. WUEEA/ o. PCTL'RSQ V United States Patent Office 2,757,400 Patented Aug. 7, 1956 BRUSH AND METHOD OF MAKING SAME Ruben 0. Peterson, University Heights, Ohio, assignor to The Osborn Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application May 31, 1952, Serial No. 290,890

7 Claims. (Cl. --179) The present invention relating as indicated to brush manufacture has more particular regard to the manufacture of so-called brush strip whether intended for use as straight line brush elements or to be bent into circular form or wound spirally to form a cylindrical brush. This application is a continuation-in-part of my co-pending application Serial No. 246,360 filed September 13, 1951 and now abandoned.

A commercial form of brush strip and method of making the same are shown and described in U. S. Patents Nos. 1,963,044 and 1,963,045 to F. J. Bickel, and an improved form or" brush strip which is at present being manufactured in large quantities is shown and described in my prior Patent No. 2,303,386. In general, a continuous layer of stranded brush material cut to desired length may be fed onto a continuous flat strip, a retaining wire or equivalent elongated retaining element is applied to such layer longitudinally of such strip and the latter is then folded into channel form so as correspondingly to fold such brush material about such retaining element. To assist in retaining the brush material in proper place as thus distributed along the strip and also to secure such elongated retaining element within the channel, the portions of the strip which are to form the side walls of the channel brush back are desirably provided with transverse teeth punched therein. In the case of the Bickel brush, such teeth are formed from the respective edge portions of the strip whereas in the construction disclosed in my aforeaid Patent No. 2,303,386 such teeth are punched up at points spaced inwardly of the strip edges. In either case, the teeth are so disposed as to overlie the retaining wire or equivalent retaining element, and obviously the brush material folded about such element will at the same time be held against shifting therealong.

Although brush strip formed as above described has enjoyed very considerable commerical success, certain problems are involved in the use of the same in special situations. Thus, for example, when a length of brush strip is to be circularized about a very small radius, the tendency to tear the channel edges of the brush back is greatly increased and is accentuated at the points where the channel sides, normally of sheet metal, have been cut when punching up the teeth. While the construction disclosed in my prior Patent No. 2,303,386 represents a considerable improvement in this regard over the Bickel type of brush, nevertheless it will be apparent that any operation actually cutting the channel walls will give rise to localized concentrations of stress therein when the brush strip is subsequently circularized or otherwise deformed. When employing bristle material in the form of relatively fine strands which are sometimes employed even in the larger sizes of brush strip but will naturally quite generally be employed when very small sizes of brush strip are to be produced, e. g. brush strip having a channelform back of a depth of less than A" and a layer of brush material extending therefrom less than /2", there may also be some tendency for the.

punched-up teeth to out such bristles since the teeth will naturally tend to have fairly sharp edges.

It is accordingly a principal object of the present invention to provide a novel brush element in which means are provided for securing an elongated retaining element within a channelform back member, such means comprising projections formed without actually severing the material of the back so that the strength of the back will not be locally reduced.

Another object is to provide such projections which will not tend to cut or otherwise damage the brush material.

Still another object is to provide a novel form of brush strip in which the brush bristle material may extend from the elongated back portion in a series of closely spaced tufts.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. l is a side elevational view of a length of my new brush strip circularized to form an annular rotary brush element;

Fig. 2 is an enlarged top plan view of a short length of backing strip having protuberances struck up therefrom;

Fig. 3 is an enlarged transverse cross-sectional view taken on the line 3-3 on Fig. 2;

Fig. 4 is a top plan view of a length of backing strip similar to Fig. 2 but showing a somewhat different form of protuberance;

Fig. 5 is an enlarged transverse cross-sectional view taken on the line 55 on Fig. 4;

Fig. 6 is an enlarged transverse cross-sectional view taken on the line 6-6 on Fig. l and showing protuberances of the Fig. 2 type;

Fig. 7 is a transverse sectional view similar to Fig. 6 but showing protuberances of the Fig. 4 type;

Fig. 8 is a side elevational view showing a length of my new brush strip being circularized and coiled into helical form with the brush bristle material extending radially;

Fig. 9 is a transverse sectional view taken on the line 99 on Fig. 8;

Fig. 10 is a side elevational view of another modification of my new brush strip; and

Fig. 11 is a side elevational view of still another modification of such brush strip.

Referring now more particularly to said drawing, the annular rotary brush section illustrated in Fig. 1 comprises a length of my new brush strip which has been circularized about a relatively small radius with the two ends of the back 1 of such strip opposed at 2 and desirably secured together as by welding, with the brush bristle material 3 extending generally radially therefrom. It will, of course, be understood that my new brush strip may be utilized in straight lengths where desired or helically wound about a mandrel, for example, to form a generally cylindrical brush element. My new brush strip is assembled in the general manner described in my aforesaid Patent No. 2,303,386, a layer of the brush material 3 being laid transversely of the backing strip 1, ordinarily of thin sheet metal such as steel, and an elongated retaining element such as wire 4 then superimposed thereon longitudinally of such strip. When the backing strip is now shaped to channel form, such layer of brush material will be folded around the retaining member as explained in such patent and also'shown in Figs. 6 and 7 of the annexed drawing.

A row of hollow protuberances 5 is struck up adjacent but slightly spaced from each edge of backing strip 1, leaving corresponding hollows 6 in the other side of such strip. Such protuberances perform the functions of the teeth in the above-mentioned prior art constructions.

As shown in Figs. 2, 3 and 6, the protuberances of the respective rows may be disposed in slightly staggered or otfset relationship so that when such backing strip is dcformed to channel shape, pairs of adjacent but not directly opposed protuberances will closely overlie and secure elongated retaining element 4 within such back. In the embodiment above described, it will be seen that the protuberances 5 are of general wedge shape having relatively abruptly sloping faces 7 toward the center of strip 1 and more gently. sloping faces 8 toward the respective edges of such strip. The protuberances 5 thus embossed in strip 1 therefore assume more or less the contour of a longitudinal conic section. As best shown in Fig. 6, the relatively abrupt shoulders 7 will overlie and bear against retaining element 4 to lock the latter in place, easily resisting any outward thrust by such element thereagainst which might otherwise tend to cam the channel sides outwardly.

The two row-s of protuberances may be only slightly staggered as described, in which case with some types of brush material there may be a tendency to divide the latter into tufts, or such rows of protuberances may be staggered or offset in a uniform manner as shown in Fig. 4, this latter arrangement resulting in somewhat more uniform distribution of the brush material.

In the embodiment shown in Figs. 4, 5 and 7, not only are the protuberances 9 arranged in uniformly offset rows but also such protuberances are of a different shape, as best shown perhaps in Fig. 5. Protuberances of this type may conveniently be formed on a small punch press using circular dies With the male die of relatively small diameter. Strip may be fed through such a press at relatively high speed and'the brush material and retaining element applied thereto and the strip shaped to channel form, all as a continuous operation. Protuberances of this latter type are particularly suitable when small sizes of brush strip are to be manufactured since they may readily be formed of very small dimensions permitting an appreciable portion 10 adjacent the edge of the strip to remain undeformed. When brush strip of such small size is to be circularized as shown in Fig. l, for example, it is of considerable importance that the width of the channel side portions be as small as possible so as to reduce the strain upon the channel edges and therefore the likelihood of tearing the same. With most strip materials such as thin steel strip, the male die forming the protuberances should not be narrower than twothirds the thickness of the strip since otherwise there may be danger of cutting through the latter.

I am aware that in the past brush strip having a channelform metal back has been produced in which indentations have been provided at spaced intervals in the edges of such channel. Such. indentations, however, merely stretch outv when the brush strip is subsequently circularized and, in any event, are incapable of closely overlying the upper surface of the wire or like retaining element. It will be appreciated that while the form of protuberance utilized may vary somewhat it is most desirable that the face of the protuberance directly overlying the elongated retaining element 4 should be approximately normal to the channel side. When this is the case, pairs of protuberances projecting inwardly from the respective sides of the channel back may even be directly opposed and yet secure a retaining element such as wire 4 sufficiently firmly therebeneath. This arrangement may sometimes desirably be utilized when the channel sides are of particularly narrow width. Ordinarily, a degree of overlap will be preferred.

Protuberances such as 5 (Figs. 2, 3 and 6) may be more or less pyramidal in shape with the side 7 sloping relatively abruptly better to secure wire 4 therebeneath. The self-supporting but deformable sheet material channel back may desirably have relatively flat sides, as shown, to facilitate assembly of a plurality of turns in close side-by-side relationship.

Figures 8-11 inclusive show modifications of the Fig. 7 protuberance, such protuberances projecting inwardly from the channel sides and having a generally uniform but non-circulnr cross-section throughout their length. When straight brush strip of the type above described is circularized about a mandrel, for example, as shown in Fig. 8, the outer edge 11 of the channel back will be stretched and such stretching will be accenuated in the regions intermediate the inwardly projecting protuberances such as 12; and such edge 11. Moreover, the shorter the side of the protuberance adjacent such edge, the more concentrated is the region of stretching intermediate such protuberances and the channel edge. Accordingly, when small sizes of brush strip are to be circularized about small diameter-s, I have found it advantageous to shape such protuberances with relatively long regions or side edges 13 parallel to or approximately parallel to such channel edges 11. Relatively long regions are accordingly afforded wherein stretching of the band of metal intermediate the protuberances and the channel edge may take place without excessive concentrations of stress and resultant tearing of the channel edge. Even if the length of a straight-line protuberance or dimple side 13 parallel to the channel edge 11 is only one-sixteenth of an inch, for example, the length of the portion of the channel edge opposite such dimple over which the stretch will be distributed will be many times greater than in the case of the Fig. 2 and Fig. 4 embodiments.

As shown in Fig. 9, the protuberances 12 need not necessarily project inwardly sufficiently directly to overlie the brush bristle retaining wire 4, but if they project sufficiently inwardly they will nevertheless tend to secure such wire in place within the channel. This effect is furthered if the edge portions of the channel back are pressed together to form a slightly constricted neck for the channel from which the brush bristle material emerges.

In the Fig. 10 embodiment, the protuberances 14 are of oval cross-section (i. e. the punch forming the same will be of oval cross-section), and accordingly the region of stretch of the channel sides between such protuberances and the channel edge 11 when the brush strip is circularized or similarly deformed will not be so abruptly concentrated in a localized region as in the case of the Fig. 4 embodiment, for example. One point on the side of such protuberance (considering it as viewed exteriorly of the channel) will, however, be closest to the channel edge 11 as contrasted to the Fig. 8 embodiment where the entire side of the protuberance is equidistant from such channel edge, and there will accordingly be a greater build up of stress.

A preferred embodiment is illustrated in Fig. 11 where the protuberances 15 (and the punch or die forming the same) are of a cross-section generally similar to that shown in Fig. 8. Thus, they have straight sides 16 parallel to the edge 11 of the channelform back, and the side of the protuberance toward the bottom of the channel will preferably be arcuate in form as shown. However, the are 17, instead of starting directly from the ends of the side 16, will preferably be separated from the ends of such side by short straight side portions 18 generally normal to side 16. This shape permits the employment of a punch or die of comparable configuration which is relatively strong and longer lived than a punch or die of the shape required to form the Fig. 8 protuberances.

It will be appreciated, of course, that where brush strip I ing generally radially outwardly, the shape of the prtuberances is not of as great importance and the sides toward the edges of the channel back need not be parallel thereto. While the construction of my novel brush strip is of particular advantage in the smaller sizes thereof, nevertheless the principles of my invention may be utilized in the manufacture of all sizes of brush strip, and I have produced large sizes of brush strip having fairly heavy steel channelform backs and wire bristle material secured therein, with such bristle material being held beneath a retaining member such as 4 secured in place by pro" tuberances of circular cross-section such as 9. As explained above and illustrated in Fig. 9 of the drawing, such protuberances need not necessarily project inwardly to the extent shown in Fig. 7 but may instead often project only as far as shown in Fig. 9 with satisfactory results.

Protuberances formed in accordance with this invention are, of course, very rigid and will not bend during the operation of forming the back into channel form. For this reason, much less care is required during such forming operation than if very small flat teeth were punched out of the channel sides in the prior art manner. Moreover, such protuberances will not tend to out even the finest bristle material. The formation of points of localized stress is greatly reduced and the back is on the whole much stronger. Very light gauge metal strip such as steel or brass, for example, may be employed in the formation of the brush back and even thin synthetic plastic material may be utilized for this purpose. In addition to the ordinary brush materials such as horsehair, tampico fiber and wire, very fine filaments or strands of such materials as Nylon and other plastic and fine wire may be utilized as the brush bristle material, for example.

When forming cup brushes and the like in which the layer of brush material extends generally parallel to the axis of circularization of the brush strip (usually somewhat flaring) it will sometimes be desirable, if the brush is of small diameter, to provide my novel protuberances on one channel side only, such side comprising the inside of the bend. The tension exerted on the channel edge of the outer side during circularization will tend to draw such edge inwardly toward such axis to cooperate with the protuberances on the inner side in securing the elongated retaining element.

I claim:

1. In a rotary brush element comprising a circularized length of brush strip having a thin sheet metal channelform back, an elongated brush material retaining element disposed longitudinally within said back, and brush material held in said back beneath said element and extending therefrom; a series of spaced, inwardly directed, hollow protuberances formed in the respective channel sides of said back and somewhat spaced from the edges thereof engaging said retaining element to secure the same in place, the sides of said protuberances adjacent said channel edges extending parallel to said edges for substantially the entire width of said protuberances to avoid undue concentrations of stress when said brush strip is deformed with consequent stretching of said channel edges.

2. In a rotary brush element comprising a circularized length of brush strip having a thin sheet metal channelform back, an elongated brush material retaining element disposed longitudinally within said back, and brush material held in said back beneath said element and extending therefrom; a series of spaced, inwardly directed, hollow protuberances formed in the respective channel sides of said back and somewhat spaced from the edges thereof to secure said retaining element in place, the sides of said protuberances adjacent said channel edges extending generally parallel to said edges for substantially the entire width of said protuberances, and the sides of said protuberances toward the base of said channel being generally arcuate.

3. In a rotary brush element comprising a circularized length of brush strip having a thin sheet metal channelform back, an elongated brush material retaining element disposed longitudinally within said back, and brush ma terial held in said back beneath said element and extending therefrom; a series of spaced, inwardly directed, hollow protuberances formed in the respective channel sides of said back and somewhat spaced from the edges thereof to secure said retaining element in place, the sides of said protuberances adjacent said channel edges extending generally parallel to said edges for substantially the entire width of said protuberances and the sides of said protuberances toward the base of said channel being generally arcuate and joined to said parallel sides by straight intermediate portions normal to said parallel sides.

In brush strip of the character described adapted to be circularized and having a self-supporting channelform base of deformable sheet material, the edges of such channel being continuous and uninterrupted, an elongated retaining element disposed longitudinally within said base, and brush material held in said base by said element and extending therefrom; a series of spaced, inwardly directed, hollow protuberances formed in the respective channel sides to secure said retaining element in place, the sides of said protuberances adjacent the edges of the latter extending substantially parallel to the latter to avoid undue concentrations of stress when said brush strip is deformed with consequent stretching of said channel edges.

5. In a brush element comprising a length of brush strip adapted to be circularized with brush material extending generally radially outwardly and having a unitaiy sheet material channelform back, an elongated brush material retaining element disposed longitudinally within said back, and brush material held in said back beneath said element and extending therefrom; a continuous series of small spaced inwardly directed hollow protuberances formed in the respective channel sides of said back and closely overlying and contacting said retaining element, the sides of said protuberances adjacent the channel edges extending parallel to such edges for substantially the entire width of said protuberances to avoid undue concentrations of stress when said brush strip is deformed with consequent stretching of said channel edges.

6. A brush element as defined in claim 5, wherein said protuberances also have faces generally normal to the channel sides contacting said elongated retaining element.

7. The method of forming an annular rotary brush element which comprises punching a series of hollow protuberances adjacent but spaced from each edge of a strip of sheet metal without cutting through such metal, such protuberances projecting to the same side of such strip and having their sides adjacent the respective strip edges also parallel thereto, disposing a layer of brush material transversely of such strip, placing an elongated retaining element upon such material longitudinally of such strip and between such series of protuberances, forming such strip to channel form enclosing such elongated element and thereby securing the latter closely beneath such protuberances, and thereafter circularizing the resultant brush element to annular form with such brush material extending generally outwardly from such channel, the edges of such channel being stretched by such circularization operation without undue concentrations of stress in view of such parallel sides of such protuberances.

References Cited in the file of this patent 

